Weeds

1. Weeds

2. Plant Body • Shoot system = leaves + stem • Root system • Meristem = cells that divide for life of plant, can give rise to all plant structures

3. Blade Petiole Plant Body Leaf = blade + petiole FunctionsExposes surface to sunlight Major site of photosynthesis Conserves water Provides for gas exchange

4. Xylem conducts water and minerals Phloem transports sugar Plant Body Stem Functions Holds leaves up to light Transport of substances through vascular tissue

5. Plant Body Root Functions Anchors plant in soil Takes up water and minerals from soil

6. 1 Tree Tobacco Nicotiana glauca glauca = bluish-gray,referring to leaf colorLeaves contain high levels of nicoteneIntroduced from South America by missionaries, from imported grain or on purpose…?

7. 2 Cheeseweed Malva neglecta Seeds and leaves are edible. Seeds are shaped like rounds of cheese.

8. Ricin in seeds --used to kill a spy on London Bridge --recently discovered in the US mail --possible cancer treatmentOil from seeds has laxative and wound-healing properties. Castor BeanRicinus communis

9. 4 Sweet fennel Foeniculum vulgare • Petioles are eaten, like celery. • Folkways medicine: Dried Leaves may repel fleas • Priests spread on mission floors for fragrance

10. 5 Scarlet Pimpernel Anagallis arvensis Folkways Medicine: May repel witches Poisonous to humans and livestock

11. 6 Poison hemlock Comium maculatum Conin causes muscle paralysis, found in all parts of plant.

12. 7 Filaree (Storksbill)Erodium • Fruit shape is long and pointed • Filaree comes from the Spanish name for needle • Erodium refers to heron • Young foliage is edible

13. Large numbers of nutritious seeds, Used by native Americans for flour 8 Saltbush Atriplex canescens

14. 9 Sweet clover Melilotus albus Enhances production of cumarin by moldsOriginal source of heparinImportant source of honey

15. 10 Opium poppy Papaver somniferum Morphine and codeine from developing seed pods

16. 11 California PoppyEschscholtzia californica Young foliage is edibleRoots used for toothache

17. 12White GoosefootChenopodium Young foliage and seeds are edible

18. 13 Mexican Tea Chenopodium ambrosioides Folkways Medicine: Seeds act against intestinal worms. Dried plant is used as seasoning.

19. 14 Horehound Marubium vulgare Flavoring in candy, cough drops, and beerFolkways Medicine: good for sore throats Member of the Mint family

20. 15 California Mugwort Artemisia douglasiana Folkways medicine: Uses for intestinal, respiratory and skin ailments.

21. 16 Jimson weed Datura meteloides All parts of plant have alkaloids like atropine. --medical use --religious observances by Native Americans --hallucinogen in the 60’s DANGEROUS! Recent hospitalizations and deaths reported in LA County.

22. 17 Sea FigCharpobrotus chilensis • Edible fleshy fruit forms below the flower • Helps to stabilize soil on hillsides or sand near ocean

23. 18 Tumbleweed(Russian Thistle)Salsola tragus • Noxious weed = targeted for eradication • Shoot breaks off close to base and is pushed by wind to distribute seeds. • Contains high levels of nitrates or soluble oxalates

24. 19 New Zealand SpinachTetragonia tetragonioides • Leaves can be eaten raw or cooked • Contains harmless levels soluble oxalates

25. 20 Water Cress Rorippa nasturtium-aquaticum • Leaves and shoots can be eaten. • Rich in Vitamin C • Be sure it comes from unpolluted waters!

26. 21 Wild celery Apium graveolens • Escaped from cultivation • Petioles are eaten • Wild plant has strong taste made milder by cooking

27. 22 ChicoryCichorium intybus • Root scrapings used as coffee flavoring or substitute • Leaves of C. endiva used in salads

28. 23 Western Ragweed Ambrosia The pollen is a common respiratory or hay-fever allergen.

29. 24 Sow Thistle Sonchus • Young leaves are edible • One species is a noxious weed

30. 25 PlantainPlatago potagonica • Young leaves are edible • Folkways medicine:wound healing, laxative

31. 26 Curly Dock Rumex crispus • Young leaves are edible • Folkways medicine: to treat cough, blood pressure, itching, sprains • Toxic to livestock

32. 27 DandelionTaraxacum officinale • Young leaves and roots are eaten • Dried roots used as coffee substitute • Seeds dispersed by wind

33. 28 Black Mustard Brassica nigra • Young leaves are eaten • Seed oil used to make mustard • Possibly introduced by missionaries who scattered it along the Camino Real to mark the way between missions

34. 29 Wild RadishRaphanus sativus Scrapings from young roots or young seed pods taste like radishes

35. 30 Wild oats Avena fatua • Escaped from cultivation • Seeds are edible

36. 31 English IvyHedera helix • Juice causes skin irritation • Berries and leaves are toxic

37. 32 Periwinkle Vinca major A related species provides treatments for Hodgkin’s disease, leukemia and other cancers

38. 33 Garden NastursiumTropaeolum majus • Leaves are eaten in salads • Hallucinogenic properties unproven

39. 34 Blue GumEucalyptusEucalyptus globosus Added as a flavoring to candies and cough medicines

40. 35 SpurgeEuphorbia • Milky sap (latex) causes skin irritation • Relative of the mildly-toxic Poinsettia plant

41. 36 Narrow-Leaf MilkweedAsclepias • Cardiac glycoside acts as • Medicinal heart stimulant • Arrow poison • Insect defense mechanism

42. 37 White and Purple NightshadeSolanum • Berries are poisonous • Relatives of the potato

43. Worksheet • Complete page 169 from lab manual • Be sure your instructor checks your completed worksheet before you leave the lab